Hydrogen storage capacity of Tin1B (n ¼ 3e7) clusters is studied and compared with that of
the pristine Tin (n ¼ 3e7), using density functional theory (DFT) based calculations. Among
these clusters, Ti3B shows the most significant enhancement in the storage capacity by
adsorbing 12 H2, out of which three are dissociated and the other nine are stored as dihydrogen
via Kubas-interaction. The best storage in Ti3B is owed to a large charge transfer
from Ti to B along with the largest distance of Ti empty d-states above the Fermi level,
which is a distinct feature of this particular cluster. Furthermore, the effect of substrates on
the storage capacity of Ti3B was assessed by calculating the number of adsorbed H2 on Ti3
cluster anchored onto B atoms in the B-doped graphene, BC3, and BN substrates. Similar to
free-standing Ti3B, Ti3 anchored onto boron atom in BC3, stores nine di-hydrogen via Kubas
interaction, at the same time eliminating the total number of non-useful dissociated
hydrogen. Gibbs energy of adsorption as a function of H2 partial pressure, indicated that at
250 K and 300 K the di-hydrogens on Ti3@BC3 adsorb and desorb at ambient pressures.
Importantly, Ti3@BC3 avoids the clustering, hence meeting the criteria for efficient and
reversible hydrogen storage media.